I had the same thing happen to me. Long ago, I sold an F-4s on photo.net. The camera was super-mint and I got a good price for it. Two weeks later the buyer e-mails me about my lying as to the description of the camera.

After telling him he was crazy through repeated e-mails back and forth, it finally came out that the idiot had smacked the camera near the bottom where the F-4s tapers off and chipped it.

I told him to have a nice life and enjoy his camera. Never heard from him again.